Example 02Beginner

Argument Parsing

Parse CLI arguments without dependencies - flags, options, and positional args

Complete Code

02_argument_parsing.rs

use zfish::Args;

fn main() {
    // Parse command-line arguments
    let args = Args::parse();

    println!("Command: {}", args.command);

    // Check for flags
    if args.has_flag("verbose") || args.has_flag("v") {
        println!("Verbose mode enabled");
    }

    if args.has_flag("help") || args.has_flag("h") {
        print_help();
        return;
    }

    // Get option values
    if let Some(output) = args.get_option("output").or_else(|| args.get_option("o")) {
        println!("Output file: {}", output);
    }

    if let Some(count) = args.get_option("count") {
        println!("Count: {}", count);
    }

    // Get positional arguments
    if !args.positional.is_empty() {
        println!("Files: {:?}", args.positional);
    }
}

fn print_help() {
    println!("Usage: {} [OPTIONS] [FILES...]", std::env::args().next().unwrap());
    println!();
    println!("Options:");
    println!("  -h, --help              Show this help message");
    println!("  -v, --verbose           Enable verbose output");
    println!("  -o, --output <FILE>     Output file path");
    println!("  --count <N>             Number of iterations");
}

Output

Command: ./program
Output file: result.txt
Count: 5
Files: ["input.txt", "data.json"]

Running the Example

Terminal

# Run with various arguments
cargo run --example 02_argument_parsing -- --verbose --output result.txt --count 5 input.txt data.json

# Show help
cargo run --example 02_argument_parsing -- --help

Next Steps

Next: Example 03 →View Source